JPS6042097A - Aqueous overcoating composition and printing method using the same - Google Patents

Abstract

PURPOSE:To provide a composition capable of enhancing the setting and drying properties of an ink when being applied onto an oil base ink being in a wet state after printing, comprising an aqueous resin dispersion, which is constituted mainly of an acrylic copolymer, and an ethylene glycol dialkyl ether. CONSTITUTION:The aqueous composition to be applied on the surface of an oil base ink being in a wet state after printing comprises (A) an aqueous resin dispersion constituted mainly of an acrylic copolymer (preferably, having an acid value of not higher than 50) and (B) an ethylene glycol dialkyl ether of the formula: R1-O-C2H2-O-R2, wherein each of R1 and R2 is 1-4C alkyl, in an amount of not less than 1wt% to the total weight of the composition, and has a property of forming a film at an atomospheric temperature in the printing operation or the heating operation (preferably, room temperature).

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to an aqueous overcoating composition and a printing method using the same, and more specifically, the present invention relates to an aqueous overcoating composition and a printing method using the same. An aqueous overcoating composition and its use for overcoating objects to prevent set-off, blocking, etc., while promoting the setting of oil-based inks and improving the workability of printing and post-processing of printed matter. The present invention attempts to provide this printing method.

BACKGROUND OF THE INVENTION At present, oil-based inks used in planographic printing, letterpress printing, etc. mainly contain resin, drying oil, and mineral oil as an inder, and are mainly dried by oxidative polymerization drying. Looking at the drying process of oil-based ink in more detail, when oil-based ink is printed on paper, a portion of the ink σ〕Ore VIDi... and drying oil σ) penetrates into the paper and becomes semi-dry on the paper. A film is formed (this state is generally called set), and then the drying oil reacts with oxygen to undergo oxidative polymerization and harden, resulting in complete drying. usually requires 15 to 60 minutes for setting and 6 to 10 hours for complete drying. In the set state, printed matter may be stacked in small quantities without causing set-off or blocking, but it may not be suitable for more extreme conditions such as stacking in large quantities or post-processing such as cutting or folding. They do not have sufficient resistance, and their suitability cannot be achieved unless they are completely dry. As mentioned above, these oil-based inks require an extremely long time to set and dry.
Drying of printing ink has been a major problem, impeding printing speed and claimed work efficiency.

Therefore, for example, in sheet-fed lithographic printing, fine powder such as starch (spray powder) is sprinkled on the printed surface immediately after printing to prevent set-off and to remove spots. The reality is that However, with this method, fine powder scatters and floats, which poses environmental hygiene problems.Also, since the fine powder is deposited on the printing surface, it deteriorates gloss and makes the surface rough, which causes a decrease in printing quality. It becomes.

In addition, even if such spray powder is not applied, the desired amount of printed matter cannot be piled up sufficiently, resulting in a significant decrease in work efficiency. Furthermore, there was no compatibility with post-processing such as bending, and the paper had to be left for several hours to wait for the ink to dry.

In addition, in rotary printing, undried ink adheres to mechanical parts such as the paper roll feed roller, tension roller, folding machine, etc. built into the printing press, and this ink transfers back onto the printed material, causing it to become smeared. When rolled up or folded printed matter is tied together, they tend to set off or block each other, making high-speed rotary printing impossible.

To prevent this, we use evaporative drying ink that mainly evaporates the bath agent in the ink, and use a large drying device such as a burner, infrared heater, and hot air to lower the paper surface temperature to 1.
30"J is heated and dried, or an ink such as UV ink that cures rapidly with active energy rays is used. However, the former ink (generally called heat set ≦ν ink) In this case, the solvent in the ink is rapidly evaporated, so energy consumption such as gas and electricity is large, and the vapor containing the solvent is exhausted, causing air pollution and odor problems. In the case of the latter, there are problems such as difficulty in obtaining printed matter with various aptitudes such as gloss.Also, in the case of the latter, special equipment is required due to the use of special reactive ink, special printing plates, Zolanket, and ink cleaning. It has not become very popular because it requires a chemical agent, the ink is expensive, and it lacks retention, stability, and workability.

Recently, for Komaru, a film of water-based coating agent is formed on the wet printed surface immediately after lithographic printing,
Coating methods have been developed for printing surfaces that improve the above-mentioned problems caused by drying of printing ink while imparting various types of resistance such as gloss.

Purpose of the invention However, the aqueous coating agent used in this method
By applying it on oil-based ink in a wet state, it is possible to cover the surface of the oil-based ink and prevent phenomena such as set-off or blocking caused by stacking printed matter, etc., to some extent. It only has the ability to cover the oil-based ink, and has no effect on accelerating the setting or drying of oil-based ink, and post-processing after printing can only be done several hours after printing, as in the past. . In addition, when water-based coating agents are applied over wet oil-based ink, they may not have sufficient adhesion, or may not have the gloss or abrasion resistance required for high-quality printed materials. This was problematic.

The present inventors have endeavored to solve the above-mentioned drying problems of oil-based inks. It has adhesive properties and not only improves the coating performance of oil-based inks, such as gloss and abrasion resistance, but also prevents set-off and blocking phenomena during stacking after printing. Alternatively, they have discovered an aqueous overcoating composition that has the effect of significantly improving drying properties, and have completed the present invention.

A non-invention aspect of the invention provides an aqueous overcoating composition for coating onto oil-based ink in a wet state after printing, the composition comprising an aqueous resin dispersion mainly composed of an acrylic copolymer.

Water containing 1% or more of ethylene glycol dialkyl ether represented by the following general formula based on the total amount of the composition, and having the ability to form a film at ambient temperature during printing or heating operations. The present invention seeks to provide four overcoating compositions.

General formula R, -0-C2H2-0-112 (where Rp
(R2 represents an alkyl group having 1 to 4 carbon atoms) A further object of the present invention is to provide a printing method using the above aqueous overcoating composition.

Hereinafter, the aqueous overcoating composition according to the present invention will be explained in more detail.

The main component is an aqueous resin dispersion, and the atmospheric temperature during printing or heating drying operation is preferably 80°C.
It is necessary to have the ability to form a film at temperatures below 0.degree. C., more preferably at the xth floor. If the temperature is 80° C. or higher, a large amount of energy is required for film formation, and a device similar to a conventional drying device is required. If the temperature is 80° C. or lower, relatively little energy is required for film formation, and therefore a simple drying device can be used, which is preferable from the viewpoint of the purpose of the present invention. It is more preferable to form a film at room temperature because it does not particularly require energy for film formation.

Such aqueous resin dispersion 1 is produced by emulsion polymerization of acrylic monomers, and the glass transition temperature (Tg) of the polymer of the acrylic monomers used is
), and by setting the polymerization ratio with other acrylic monomers, the film-forming temperature of the desired dispersion can be adjusted, and the dispersion that forms a continuous film at the desired temperature can be adjusted to can be built. In setting Tg, the multiplication ratio is set according to Wood's approximation formula, and the desired Tg dispersion can be obtained.

In this case, the film forming temperature should be 80°C or less, more preferably at room temperature, taking into consideration the atmospheric temperature during application of the dispersion and the heating energy given for continuous film formation as necessary. It is desirable to use it. Examples of acrylic monomers that can be used to synthesize the above dispersion include the following. First, relatively high T
An acrylic monomer can be used to obtain a polymer of g. Furthermore, examples of acrylic monomers capable of obtaining polymers with relatively low Tg include alkyl esters of acrylic acid or methacrylic acid other than the above-mentioned methyl methacrylate and methacrylic 1-ethyl esters, such as methyl, ethyl, propyl, and isomeryl.

Lopyl, n-butyl, S-butyl, t-butyl.

Examples include esters having tiua or side chain alkyl groups such as hexyl and lauryl. In addition, it is also possible to copolymerize other acrylic monomers in addition to the above-mentioned monomers, and examples thereof include acrylic monomers having functional groups such as unsaturated carboxylic acids such as acrylic acid and methacrylic acid.

-- However, if a monomer having a functional group is used among the monomers mentioned above, it may not be possible to obtain a stable dispersion. Because it may have a negative effect on resistance such as chemical resistance, = IIiJJ = ÷ Yokoshiba Todoroyu → 4 It is important that the acid value is 50 or less, and if it is higher than that, water resistance, drying properties, and film forming properties Depending on the intended use,
It is necessary to adjust its usage.

To obtain these dispersions, the monomers mentioned above may be stably dispersed by emulsion polymerization using a hydrophilic catalyst such as ammonium persulfate, potassium persulfate, or water peroxide 15 or a redox catalyst by a generally known method. An emulsifier can also be added depending on the situation.

K. Copolymerization can be carried out in an emulsified state, but in general, the use of low-molecular-weight activators may have a negative effect on the water resistance, chemical resistance, etc. of the resulting film, so water resistance is particularly required. In such cases, polymer anionic activators are suitable as emulsifiers.

The aqueous dispersion resin according to the present invention also has excellent performance by using such an emulsifier. Examples of such polymeric emulsifiers include shellac and acrylic acid-based or maleic acid-based copolymers having carboxyl groups, and aqueous alkaline solutions thereof can be used. As mentioned above, it is also possible to set the desired film-forming temperature for the emulsion polymerized dispersion itself and use a dispersion made of one copolymer resin, but it is also possible to use a dispersion made of a polymer with a relatively high Tg. The desired dispersion can also be obtained by preparing a dispersion of a polymer and a polymer having a relatively low Tg, applying the dispersion to the above-mentioned Wood's equation, and blending these dispersions (polymer blend).

The solvent added to the aqueous resin dispersion is represented by the following general formula, and is 1% by weight or more, preferably 1 to 1% by weight, based on the total amount of the aqueous overcoating composition.
It is necessary to have a weight of 8v, more preferably 3 to 5%. If the amount added is less than 1% by weight, the desired effect of the present invention cannot be obtained, and if it is more than 8% by weight, it may adversely affect the storage stability of the dispersion.
do not have.

The solvent to be added has the general formula R1-o-c2H,,-
o-R2 (however, R1 and R2 represent an alkyl group having 1 to 4 carbon atoms), specifically, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol shisotyl ether, ethylene glycol methyl Examples include butyl ether, ethylene glycol methyl butyl ether, and ethylene glycol methyl butyl ether.

Conventional aqueous coating agents include alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol, polyhydric alcohols such as ethylene glycol, fluoropylene gellicol, diethylene glycol, and glycerin, ethylene glycol monomethyl ether, and ethylene glycol monomethyl ether. Water-miscible solvents such as cellosols such as ethyl ether were added as appropriate to control the drying properties of the coating agent, but these solvents were only effective in controlling the drying properties of the coating agent. However, for the oil-based ink that forms the lower layer,
It did not contribute in any way to improving its setting properties and drying properties.

However, the aqueous overcoating composition composed of the aqueous resin dispersion and the above-mentioned specific solvent according to the present invention exhibits a remarkable effect on improving the setting properties or drying properties of the oil-based ink in the lower layer, and is effective in improving the setting or drying properties of the oil-based ink immediately after printing. When applied in layers, processing such as cutting or bending can be performed immediately after application, and post-processing that could previously only be done after a certain amount of time has passed after printing can be performed immediately, offering extremely excellent performance. It is something. The composition for aqueous overcoating according to the present invention is mainly composed of the above-mentioned aqueous resin dispersion and the above-mentioned solvent. From the viewpoint of improving coating film performance such as abrasion resistance after drying of the product, 0 to 15% by weight of water-soluble pheno may be added to the aqueous overcoating composition as necessary. In this case, the water-soluble phenol to be used can be an aqueous solution of an alkali-soluble resin that has been conventionally used as a phenol in water-based printing inks. An alkaline aqueous solution of casein-based resin can be used. Adding a large amount of this water-soluble pheno will reduce drying properties, but it will also have a large effect on film-forming performance, which may impede the improvement of setting properties, which is the objective of the present invention, so care must be taken when using it. shall be. The pond water-based overcoating composition can contain optional ingredients as needed, and each is added in consideration of various coating film performances such as viscosity adjustment, drying adjustment, gloss, and abrasion resistance, or leveling. Agent 1 For example, alcohol, antifoaming agent.

Waxes, various weighing agents, and 111H1 agents can also be added.

Further, the printing method using the above-mentioned aqueous overcoating composition can be carried out by the following means. The following means can be used to coat the oil-based ink in a wet state immediately after printing using the aqueous overcoating composition as described above. One method is to incorporate a coating device after the final printing unit of the printing press to coat the printed product immediately after printing.

FIG. 1 shows a case where a coating device is installed after the final printing unit, where ◯ indicates the final printing unit, ◯ indicates the coating device, and Q) indicates a drying device that is provided as required.

Although Fig. 1 illustrates a general roller coating unit, it goes without saying that other coating methods such as Evaspray coating, air knife coach ink, engraft roll coating, etc. can be applied. It is.

As another coating method, for example, in the case of lithographic printing, a surplus printing unit of a lithographic printing machine can be used and a conventional dampening water supply device can be used to coat the printed matter immediately after printing.

Figure 2 shows a specific example of coating with an aqueous overcoating composition using a conventional general final printing unit. Using the aqueous overcoating composition according to the present invention instead of dampening water, press the printing plate ■ from the dampening water supply device ■ (after performing operations such as changing the printing plate to a coating pattern as necessary) The coating is applied through the blanket ■.

Alternatively, as shown in Fig. 3, the plate cylinder [F] and the blanket are separated in the final printing unit, and a device (2) is provided for directly supplying the aqueous overcoating composition to the blanket. can be coated.

By using the various coating methods explained above, it is possible to apply a desired coating on the oil-based ink in a wet state immediately after printing (online or inline), which is not conventionally used. The purpose of the present invention can be achieved without special modification of the existing printing machine (or by incorporating a simple coating device).

In this way, by coating the aqueous overcoating composition on the wet oil-based ink immediately after printing, and heating the composition to form a film as necessary, not only high-speed printing suitability but also immediate post-processing can be achieved. It also has aptitude and is extremely advantageous for increasing the efficiency of printing work and post-processing work.

In addition, the aqueous overcoating Kawamei 5y according to the present invention
The film-forming performance, gloss, various resistances, etc. can be improved by adding various additives as necessary.

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples.

dispersions 1 to 10 according to conventional emulsion polymerization methods.
An aqueous resin dispersion was obtained as shown below.

In addition, as an emulsifier, an acrylic copolymer (Joncr
An ammonia aqueous solution of yl 67 (manufactured by Johnson, & Son) was used.

The nonvolatile content of the aqueous resin dispersion was adjusted to about 45%, and the nonvolatile content of the acrylic copolymer as a dispersant was adjusted to about 6% of the width of the aqueous resin dispersion.

Synthesis Example 2 Using Dispersion 6 and Dispersion 5 obtained in Synthesis Example 1, each dispersion was polymer blended at a ratio of 20:80.40:60, and each dispersion was blended with Dispersions 11 and 12. did.

Examples 1 to 12 and Comparative Examples 1 to 8 In Synthesis Examples 1 and 2, Koda Dispersions 1 to 12 were used, and according to Table 2, for 95% by weight of each dispersion, the solvent specified in the present invention and the conventional aqueous Aqueous overcoating compositions were prepared by adding and mixing 5% by weight of each of the solvents commonly added to dispersions and the like.

Printing Test 1 In order to evaluate the drying properties of the aqueous overcoating composition according to the present invention and the setting promotion effect on oil-based ink, paper laminated with aluminum foil was used instead of ordinary paper, and minerals in oil-based ink were used. The following tests were conducted in a state where penetration of oil and the like into the paper was inhibited.

Using the R1 tester, print with ordinary offset ink as oil-based ink on the aluminum surface of paper laminated with aluminum foil. The respective aqueous overcoating compositions obtained in Examples 1 to 2.4 to 12 and Comparative Examples 1 to 8 were used on the wet ink immediately after printing, and the atmosphere temperature was 25° with a bar coater. Coating was carried out under conditions C, and the drying properties of the overcoating composition and the setting state of the offset ink were examined. The results are shown in Table-6.

Table 6 Evaluation method 1, drying property: After applying the aqueous coating agent, rub the surface with a comb spatula, check the drying time of the coating agent, and rate those that dry within 20 seconds as ○ and 20 seconds to 1. Those that took minutes were evaluated as △, and those that took more than 1 minute were evaluated as ×.

2. Setting state of offset ink After applying the aqueous coating agent, it was left to stand for 90 seconds, cellophane tape was pasted on the coating agent, and evaluation was made as follows based on the difference in the peeling state of the cellophane tape.

In other words, when the offset ink is set, a type of cohesive rupture does not occur within the ink layer, so when the Sellotape is peeled off, the tape/overlay is maintained with sufficient peeling strength. If the interface of the coating agent or the offset ink/aluminum foil is smudged, the set is marked O, and even if there is cohesion and cracking between the offset ink layers, the setting is completed after 5 minutes. If the set was not completed even after the test was completed, it was evaluated as ×.

As is clear from the above results, the aqueous overcoating composition to which the solvent specified in the present invention is added has excellent drying properties of the coating agent itself, and has a significant effect on improving the setting of oil-based inks. I understand that. However, the first water-miscible solvent commonly used in the past,
Although the coating agent itself can be dried to some extent due to the evaporation properties of the bath agent, it is found that it has no effect on setting.

Examples 16 to 18 and Comparative Example 9 In order to investigate the difference in effects depending on the amount of solvent added as determined in the present invention, 8% of the mixed solvent shown in Table 4 was added to 1.92% by weight of the dispersion at different ratios. % by weight to prepare an aqueous overcoating composition.

In addition, each of the prepared coating compositions was evaluated in the same manner as in Printing Test 1, and the results are listed in Table 4.

From the above results, it can be seen that the aqueous coating agent containing 1% by weight or more of the solvent specified in the present invention can significantly improve the setting of offset ink. Incidentally, when 8% by weight or more is added, a sufficient effect can be obtained in terms of improving set, etc., but it is not sufficient in terms of storage stability.

Examples 19 to 21 Comparative Example 10 Aqueous overcoating composition specified in the present invention (
An aqueous solution of phen (acrylic copolymer, ammonia water bath solution of Jchncryl 67, resin content 30%) was mixed with the dispersion (1.9Sif weight%, ethylene glycol diptyle ether 5%), and the same aqueous overlay was prepared. A coating composition was prepared as shown in Table 5, and the difference in effect due to the addition of aqueous fen was evaluated. Note that the same evaluation as in Printing Test-1 was performed and is added to Table-5.

Table 5 From the above results, the addition of aqueous solution type fen by weight has a
It shows a tendency to inhibit the setting properties of offset ink, and the amount of fen needs to be 15% or less.

Printing Test-2 As a case of coating continuously with the printing process, a normal lithographic printing ink was used on a lithographic sheet-fed four-color machine.

Perform carton printing, cut out 20 sheets of printed matter coated with the aqueous overcoating composition, and weigh 5 kg/
They were piled up under a load of cIr12, and the presence or absence of set-off after 1 hour was evaluated. In addition, the printed portion of the printed material immediately after application was cut using a slicing machine, and the presence or absence of wrinkles was evaluated. The results are shown in Table-6.

Note that the aqueous overcoating III composition was supplied from the dampening water device of the last printing unit (fourth color), and applied to the printed surface on which six colors were printed. The printing conditions were 25° C. and a printing speed of 6000 sheets/hour. In addition, if coating compositions such as Toshideki-Jyugakubuna 1, 2.8.11 and Comparative Examples 1.2, 4.7 are used, and if not coated, a standard amount of a normal voice transfer prevention agent (spray powder) is used. did.

Table 6 1-32) (Note 1)...Blocking caused by the coating agent (Note 2)...Ink offset occurred.As is clear from the above results, the water-based Coating compositions that use coating compositions have excellent drying and setting properties, and are free from set-off and
No blocking occurred. Furthermore, even if the product coated with the aqueous overcoating composition according to the present invention is cut immediately after printing on the paper, no fading phenomenon due to insufficient drying of the oil-based ink occurs, which not only improves printing workability, but also improves the post-printing process. This significantly improved processing workability. On the other hand, in the case of the comparative example, the fading phenomenon was not improved until several hours had passed after application.

Printing Test-6 As a case where the printing process, coating process, and heating process are performed continuously, a low-temperature drying type heat set ink is used in a planographic rotary printing machine, and a gravure coater is installed between the printing machine and the dryer, Examples 1.2.6, mother, 11.14. on the printed side.
The aqueous overcoating compositions of Comparative Example 1.19 and Comparative Example 1.2.4.7 were applied. The printing conditions were 25℃,
A dryer consisting of a burner and hot air was used at a printing speed of 2-300 m/min to measure the heating conditions of the dryer when the various guide rollers were not stained during the printing paper discharge process. Furthermore, we investigated the occurrence of stains at the fold edges where the printed matter is folded, and the occurrence of blocking after the printed matter was cut and delivered.

The results are shown in Table-7.

From the above results, by using the aqueous overcoating composition according to the present invention, it is possible to significantly lower the dryer temperature of a rotary lithographic printing press, and furthermore to eliminate heating.

In addition, there was no staining caused by belts or the like in the folding machine, nor did set-off or blocking occur after binding.

(Note 1) and (Note 2) in Table-7 have the same meanings as in Clothing-6 above.

[Brief explanation of drawings]

FIG. 1 shows an embodiment in which a coating device is included after the final F1+ printing unit. FIG. 2 shows an embodiment in which a conventional final printing unit is used to coat the aqueous overcoating composition of the present invention in place of the conventional fountain solution with the oil-based ink supply means separated from the printing plate. FIG. 6 shows an embodiment in which the blanket is coated with the aqueous overcoating composition while the plate and blanket are separated in the final printing unit. 1: final printing unit, 2: coating device, 6: drying device, 4: oil-based ink supply means, 5: dampening water supply device, 6: printing plate, 7: blanker 1.8: printing paper. Patent applicant: Narita Shokai Co., Ltd. (6 others) Figure 1 Figure 2 Figure 3 Commissioner of the Japan Patent Office Kazuo Wakasugi 1. Indication of the case Patent Application No. 151055 of 1988 2. Name of the invention Composition for aqueous mever coating Product and printing method using the same 6 Relationship with the person making the amendment Patent applicant address name Sakata Shokai Co., Ltd. 4 Agent 5 Specification subject to amendment [Claims] and [Detailed description of the invention] Il¥ ((Attachment)) (1) The statement in [Claims] is amended as follows: ``1. Water-based overcoating to be applied on the oil-based ink printed surface in a wet state immediately after printing. In the composition for use, the composition comprises an aqueous body fat dispersion mainly composed of an acrylic copolymer, and a compound having the general formula R, -0-C2.
Contains 1% by weight or more of ethylene glycol dialkyl ether represented by H2-0-R2 (where R2 represents an alkyl group having 1 to 4 carbon atoms) based on the total amount of the composition, and does not require printing or heating. An aqueous overcoating composition characterized by having the ability to form a film at ambient temperature during a drying operation. 2. The aqueous overcoating composition according to claim 1, which forms a film at an ambient temperature of 80C or lower. - Coating composition. 4. The aqueous overcoating composition according to any one of claims 1 to 4, wherein the aqueous resin dispersion has an acid value of 50 or less. 5. Claims 1 to 5 containing 1 to 8% by weight of ethylene glycol dialkyl ether
2. The aqueous overcoating composition according to any one of Items 1-1. 6. Aqueous # mainly composed of acrylic copolymer
I fat dispersion and general formula, R1-0-C2H2-0-R2
Contains 1% by weight or more of ethylene glycol dialkyl ether (Ft, , R2 represents an alkyl group having 1 to 4 carbon atoms), and has the ability to form a film at ambient temperature during printing or heating drying operations. A printing method characterized by applying an aqueous overcoating composition in the form of a thin film onto a wet oil-based ink printing surface on a printing machine immediately after printing the oil-based ink or during a printing process. 7. The printing method according to claim 6, characterized in that a coating device is installed after the final printing unit of the printing press, and the aqueous overcoating composition is applied by the coating device. 8. The printing method according to claim 6, wherein the aqueous overcoating composition is applied using a dampening water supply device of a final printing unit of a lithographic printing press. 9. The printing method according to claim 6, characterized in that the coating is carried out by providing a device for supplying the aqueous overcoating composition to the blanket of the final printing unit of the lithographic printing press. (2) In Table 1 on page 21 of the specification, columns 9 and 10 for dispersion groups are corrected as follows. (3) The following will be added under Statement No. 22 Sadasue. ``In addition, Comparative Example 1 shows the case where the dispersant is 100% 0'' (
4) Table 2 on page 26 of the specification is corrected as follows.O (6) In table 4 on page 27 of the specification, the column for Example 18 is corrected as follows. (Comparative example column 10 in Table 6 on page 60 of the specification is corrected as follows. (9) The statement in the specification is corrected as follows. Page Line Original statement Correction statement 12 2 Acrylic acid For example, acrylic acid 14 7 In the present invention 25 of the present invention Lower 10 Com Rubber 288JchnorylJohncry128 16
Table-5 The results are shown in Table-5.

Claims (1)

[Claims] 1. A water-based overcoating composition to be applied onto a wet oil-based ink print surface immediately after printing.
In the snout, the composition comprises an aqueous resin dispersion mainly composed of an acrylic copolymer, and a compound of the general formula R1-0-C2.
I(2-0-R2 (However, Rt, 1g is carbon number 1-4
ethylene glycol dialkyl ether t [1% by weight based on the total composition 31]
An aqueous overcoating composition which contains the above components and has the ability to form a film at ambient temperature during printing or heating and drying operations. 2. The aqueous overcoating composition according to claim 1, wherein the aqueous overcoating composition forms a film at an ambient temperature of 80° C. or lower. 6. An aqueous overcoating composition or an aqueous overcoating composition according to claim 1, which forms a film at room temperature. 4. The aqueous overcoating composition according to any one of claims 1 to 4, wherein the aqueous resin dispersion has an acid value of 50 or less. 5. Claims 1 to 5 containing 1 to 8% by weight of ethylene glycol dialkyl etherification
2. The aqueous overcoating composition according to any one of Items 1-1. 6. An aqueous resin dispersion mainly composed of an acrylic copolymer and a general formula R8-〇-C2H2-0-R2(
However, R□ and R2 represent an alkyl group having 1 to 4 carbon atoms)
An aqueous overcoating composition containing 1% by weight or more of ethylene glycol dialkyl ether represented by Alternatively, a method is characterized in that the oil-based ink is applied in a thin film onto the wet printing surface during the printing process. 7. A printing method according to claim 6, characterized in that a coating device is installed after the final printing unit of the Z printing press, and the aqueous overcoating composition is applied by the coating device. The printing method described in item 6 within the scope of . 9. The printing method according to claim 6, characterized in that a device is provided for supplying the aqueous overcoating composition to the blanket of the final printing unit of the lithographic printing press.